<template>
  <div :class="isShowBox1 ? 'art-cmt-container-1' : 'art-cmt-container-2'">
    <!-- 评论列表 -->
    <van-list
      class="cmt-list"
      v-model="isloading"
      :finished="finished"
      finished-text="没有更多评论了"
      :immediate-check="false"
      @load="onLoad"
    >
      <!-- 评论的 Item 项 -->
      <div
        class="cmt-item"
        v-for="item in cmtlist"
        :key="item.com_id.toString()"
      >
        <!-- 头部区域 -->
        <div class="cmt-header">
          <!-- 头部左侧 -->
          <div class="cmt-header-left">
            <img :src="item.aut_photo" alt="" class="avatar" />
            <span class="uname">{{ item.aut_name }}</span>
          </div>
          <!-- 头部右侧 -->
          <div class="cmt-header-right">
            <van-icon
              name="like"
              size="16"
              color="red"
              v-if="item.is_liking"
              @click="delLike(item)"
            />
            <van-icon
              name="like-o"
              size="16"
              color="gray"
              v-else
              @click="addLike(item)"
            />
          </div>
        </div>
        <!-- 主体区域 -->
        <div class="cmt-body">
          {{ item.content }}
        </div>
        <!-- 尾部区域 -->
        <div class="cmt-footer">{{ item.pubdate | dateFormat }}</div>
      </div>
    </van-list>
    <!-- 底部添加评论区域 - 1 -->
    <div class="add-cmt-box van-hairline--top" v-if="isShowBox1">
      <van-icon name="arrow-left" size="18" @click="$router.back()" />
      <div class="ipt-cmt-div" @click="showBox2">发表评论</div>
      <div class="icon-box">
        <van-badge :content="cmtCount" :max="99">
          <van-icon name="comment-o" size="20" @click="gotoCmtList" />
        </van-badge>
        <van-icon name="star-o" size="20" />
        <van-icon name="share-o" size="20" />
      </div>
    </div>

    <!-- 底部添加评论区域 - 2 -->
    <div class="cmt-box van-hairline--top" v-else>
      <textarea
        placeholder="友善评论、理性发言、阳光心灵"
        @blur="hideBox2"
        ref="textRef"
        v-model="cmt"
      ></textarea>
      <van-button type="default" :disabled="cmt.length === 0" @click="pubCmt"
        >发布</van-button
      >
    </div>
  </div>
</template>
<script>
import { getCmtListAPI, addLikeCmtApi, delLikeCmtApi, pubCmtApi } from '@/api/articleApi.js'
// 从 popmotion 中按需导入 animate 动画函数
import { animate } from 'popmotion'
export default {
  name: 'ArtCmt',
  // 自定义属性
  props: {
    artId: {
      // 在指定属性值类型时，通过数组，可以定义多个可选的值类型
      type: [String, Number],
      required: true
    }
  },
  data () {
    return {
      cmtlist: [],
      offset: null,
      // 是否正在进行上拉加载
      isloading: false,
      // 所有数据加载完毕
      finished: false,
      // 是否展示评论区域1（如果值为 true 则展示评论区域1；如果值为 false 则展示评论区域2）
      isShowBox1: true,
      // 总评论数
      cmtCount: 0,
      // 输入框数据
      cmt: ''
    }
  },
  created () {
    this.initCmtList()
  },
  methods: {
    // 初始化评论列表数据
    async initCmtList () {
      const { data: res } = await getCmtListAPI(this.artId, this.offset)
      if (res.message === 'OK') {
        //  为offset赋值
        this.offset = res.data.last_id
        // 为总评论数赋值
        this.cmtCount = res.data.total_count

        // 为comlist赋值
        this.cmtlist = [...this.cmtlist, ...res.data.results]
        // 重置loading状态
        this.isloading = false
        // 判断数据是否加载完成，重置finished状态
        if (res.data.results.length === 0) {
          this.finished = true
        }
      }
    },
    onLoad () {
      this.initCmtList()
    },
    // 评论点赞
    async addLike (cmt) {
      const { data: res } = await addLikeCmtApi(cmt.com_id.toString())
      if (res.message === 'OK') {
        // 修改点赞状态
        // 在客户端直接修改点赞状态
        // cmt.is_liking = true
        this.$set(cmt, 'is_liking', true)
      }
    },
    // 评论取消点赞
    async delLike (cmt) {
      const res = await delLikeCmtApi(cmt.com_id.toString())
      if (res.status === 204) {
        // 修改点赞状态
        cmt.is_liking = false
      }
    },
    // 展示第二个评论区域
    showBox2 () {
      // 下一行代码一瞬间完成了
      this.isShowBox1 = false
      // 把回调函数延迟到下次DOM更新之后再执行
      this.$nextTick(() => {
        this.$refs.textRef.focus()
      })
    },
    // 隐藏第二个盒子区域
    hideBox2 () {
      setTimeout(() => {
        this.isShowBox1 = true
        this.cmt = ''
      }, 100)
    },
    // 发布评论
    async pubCmt () {
      try {
        const { data: res } = await pubCmtApi(this.artId, this.cmt)
        if (res.message === 'OK') {
          // 弹个窗
          this.$toast.success('发布成功')
          // 为服务器响应的评论对象，追加is_liking属性，默认false
          // res.data.new_obj.is_liking = false
          // 把最新的评论添加评论列表最前面
          this.cmtlist.unshift(res.data.new_obj)
          // 评论自增1
          this.cmtCount++
        }
      } catch {
        this.$toast.success('此文章拒绝评论')
      }
    },
    gotoCmtList () {
      animate({
        // 起始值
        from: window.scrollY,
        // 目标值
        to: document.querySelector('.article-container').offsetHeight,
        // 滚动的回调
        onUpdate: latest => window.scrollTo(0, latest)
      })
    }
  }
}
</script>
<style lang="less" scoped>
.cmt-list {
  padding: 10px;
  .cmt-item {
    padding: 15px 0;
    + .cmt-item {
      border-top: 1px solid #f8f8f8;
    }
    .cmt-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      .cmt-header-left {
        display: flex;
        align-items: center;
        .avatar {
          width: 40px;
          height: 40px;
          background-color: #f8f8f8;
          border-radius: 50%;
          margin-right: 15px;
        }
        .uname {
          font-size: 12px;
        }
      }
    }
    .cmt-body {
      font-size: 14px;
      line-height: 28px;
      text-indent: 2em;
      margin-top: 6px;
      word-break: break-all;
    }
    .cmt-footer {
      font-size: 12px;
      color: gray;
      margin-top: 10px;
    }
  }
}
// 外层容器
.art-cmt-container-1 {
  padding-bottom: 46px;
}
.art-cmt-container-2 {
  padding-bottom: 80px;
}

// 发布评论的盒子 - 1
.add-cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  box-sizing: border-box;
  background-color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 46px;
  line-height: 46px;
  padding-left: 10px;
  .ipt-cmt-div {
    flex: 1;
    border: 1px solid #efefef;
    border-radius: 15px;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    padding-left: 15px;
    margin-left: 10px;
    background-color: #f8f8f8;
  }
  .icon-box {
    width: 40%;
    display: flex;
    justify-content: space-evenly;
    line-height: 0;
  }
}

.child {
  width: 20px;
  height: 20px;
  background: #f2f3f5;
}

// 发布评论的盒子 - 2
.cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  padding-left: 10px;
  box-sizing: border-box;
  background-color: white;
  textarea {
    flex: 1;
    height: 66%;
    border: 1px solid #efefef;
    background-color: #f8f8f8;
    resize: none;
    border-radius: 6px;
    padding: 5px;
  }
  .van-button {
    height: 100%;
    border: none;
  }
}
</style>
